WD Coil

My WD needs a coil and the parts store had to know if it internal resistor or not. It is a delco remy on there now but it doesn't say if it is internal or not. The tractor is still 6 volt. How can I tell which one to get? Thanks

6 volts means no internal resister and if you told them that it was 6 volts they should have known that if they where worth there salt that is. Now if you said 12 volts then it would be a different story

Sounds like the typical parts man these days, they no nothing about the older equipment. Around here the are annoyed when you ask about parts for older equipment.

For your and the others general information, THERE ARE HARDLY ANY COILS, 6 OR 12 VOLTS, THAT CONTAIN ANY INTERNAL STAND ALONE DISCRETE "RESISTORS".

YES there were a few very old, mostly automotive, coils that contained hidden inside the can (often a ringed seperate compartment) a stand alone discrete "resistor".

HOWEVER what many lay people refer to as "internally ballasted" or a coil with an internal ballast/RESISTOR IS NOT USUALLY THE CASE. Whats commonly used on a coil thats designed for nominal 12 volt operation is EITHER additional windings OR higher resistance wire, such that the total primary winding resistance is in the 3 ohm range so theres around a 4 amp draw which the points have to carry and switch on and off so they dont burn up prematurely. IF YOU DONT BELIEVE ME JUST OPEN A COIL AND SEE IF YOU FIND A RESISTOR IN THERE???????????????????????????????????

Coils labeled "12 volts" OR "12 volts NO external ballast required" are designed for 12 volts and some call them "internally ballasted" HOWEVER a coil labeled "12 volts, for use with external ballast resistor" is in essence a 6 volt coil and the voltage dropping (12 to 6) external ballast is indeed needed or the coil will overheat........

Soooooooooooo call them coils with an internal resistor or internally ballasted if you like BUT I BET THERES NO "RESISTOR" INSIDE THEM!!!!!!!!!!!!!!! However, a 12 volt coil has enough wire/windings or wire with sufficient X ohms per unit length resistance such that the total primary resistance is in the 2.5 to 4 ohms range (3 typical) so that NO EXTERNAL BALLAST IS REQUIRED I will grant you that.

I call wire wire and a resisTOR a resisTOR even though even pure copper wire still has some albeit slight degree of resistANCE.......

THE GENTS ARE RIGHT, a 6 volt coil usually CONTAINS NEITHER an internal "resistor" nor internal wire/coil windings containing a total resistance much over 2 ohms (1.5 typical) and a good parts man wouldnt ask the question if you asked for a 6 volt 50 or 60's vintage tractor coil. Although, if you asked for a 12 volt coil, its a legimitate question to ask if it uses an external ballast or not, and if so it will be labeled "12 volts for use with external ballast" If NOT, its labeled "12 volts" or "12 volts NOT for use with ballast" BUT AGAIN I DONT THINK YOU WILL FIND ANY RESISTORS INSIDE IT LOL

Yall take care now, hope this helps

John T

Sadly, they are trained to deal with only fast-moving modern parts and a request for older stuff doesn't fit that business model and is FROWNED upon by management (even though such parts must carry about the same markup as the newer stuff and STILL put cash in the till).

(My 23-y-o son has worked several auto parts jobs these last 6 or 8 years and LOVES helping folks with the older stuff and the customers LOVE the attention he gives them and ASK for him on his days off, but management frowns 'cuz you aren't supposed to spend over a few seconds with a customer and taking the time to find obscure parts simply is UNACCEPTABLE, even if there's no one else in the store and he has nothing else to do.)

In other words, "don't criticize a man 'til you've walked in his moccasins", the parts guy is probably following "company policy"!!